细菌强化修复电子废弃物污染农田土壤研究

Bacteria-Enhanced Remediation of Electronic-Waste Polluted Farmland Soil

通过富集、驯化、分离,从清远市电子废弃物拆解区污染土壤中得到四种耐性菌株,经菌落形态、扫描电镜分析以及16S r DNA技术鉴定得出菌株HS-01、JH-02、YB-03、JY-04分别为海水芽孢八叠球菌(Sporosarcina aquimarina)、佐吕间湖生芽孢八叠球菌(Sporosarcina saromensis)、巨大芽孢杆菌(Bacillus megaterium)、甲基营养型芽孢杆菌(Bacillus methylotrophicus)。选取非矿山型东南景天(Sedum alfredii)为实验植物,在温室盆栽实验条件下,强化修复模拟的Cd、Cu、Pb污染土壤。结果显示添加细菌JH-02的东南景天地上部重金属提取量相对最高,JY-04次之,均显著高于其他各组(P<0.05);重金属形态分析显示细菌JH-02与JY-04对土壤重金属的活化作用相对最好,可交换态含量明显高于其他两种细菌组与未加菌组(P<0.05)。实验结果表明,JH-02与JY-04这两种细菌可能通过代谢活动产生的分泌物溶解了土壤中重金属,最终促进了东南景天的提取以及根部重金属向茎叶中转移,可达到强化修复的效果,具有一定的应用前景。

Qingyuan is one of the biggest electronic waste(e-waste)dismantling areas in China. Over 20-year operations of individual ewaste workshops there have resulted in severe pollution of the surrounding soils by Cd, Cu and Pb. Remediation of e-waste polluted soils has drawn scientific and public attentions. In our previous study, four strains of metal tolerant bacteria were identified from the soils contaminated by e-wastes in Qingyuan, using colony morphology analysis, scanning electron microscope and 16 S r DNA technology. They were Sporosarcina aquimarina(HS-01), Sporosarcina saromensis(JH-02), Bacillus megaterium(YB-03) and Bacillus methylotrophicus(JY-04). Here we used these four strains and a non-contaminated ecotype of plant Sedum alfredii to test their potential for remediating soils polluted by Cd, Cu and Pb under greenhouse conditions. Results show that the shoots of S. alfredii accumulated the highest amount of heavy metals in the presence of JH-02 bacteria, followed by JY-04 bacteria. Bacteria JH-02 and JY-04 exhibited better performance in mobilizing heavy metals, and exchangeable metal fraction was significantly higher in the JH-02 and JY-04 treatments than in other bacterial treatments(P<0.05). Our present study suggest that the bacteria JH-02 and JY-04 may be able to enhance the extraction of soil heavy metals by S. alfredii, and thus have a potential to be applied to the field.